Agricultural harvesting machines are designed to harvest crops. They have headers designed to cut or collect crops from the ground, which are then processed in the body of the harvesting machine, or directly deposited on the ground. In case of a combine, the harvesting machine threshes the crops, separates the grain from material other than grain (MOG), cleans the grain, and stores the grain in a grain tank. Eventually, they transfer the grain from the grain tank to an accompanying vehicle such as a grain cart or grain wagon. In case of a forage harvester, the crop is cut, accelerated and blown into a container of a transport vehicle, and in case of a windrower, the crop is cut and deposited on a field in a swath.
A typical header of a combine for harvesting small grain like wheat or barley is a so-called platform, which comprises a knife bar, a reel and a transverse conveyor. The knife bar cuts the stalks of the crop from the roots remaining in the ground, and the transverse conveyor, which can be an auger or a belt conveyor, feeds the crop transversely to the feederhouse which on its end feeds it into the interior of the combine harvester for threshing and further processing. The reel is located above the knife bar and rotates to engage with fingers into the crop to feed the crop rearwardly such that it can be cut by the knife bar. The cut crop is conveyed to the rear by at least one of the reel fingers and subsequently harvested crop until it is engaged by the transverse conveyor. Such a platform header can also be used on a forage harvester for providing silage of entire grain plants and on a windrower.
A number of automations of work parameters of platforms, which had to be controlled in the past manually by the harvesting machine operator, have been proposed. For example, the position of the header over ground and thus the cutting height can be controlled automatically based on sensors in a ground-contour following manner (U.S. Pat. No. 6,616,570 B2).
Another possible adjustment of some embodiments of platform headers is the table length, i.e. the distance between the knife bar and the transverse conveyor in a length-variable platform. It was proposed to control the table length automatically dependent on the crop height (WO 2014/023632 A1).
A further work parameter of a cutting platform of a combine to be controlled is the reel position. It was proposed to sense the position of the top of the crop with an ultrasonic sensor (GB 2,173,309 A) or with a camera (EP 2,681,984 A1) or with a combined RADAR and LIDAR sensor (EP 2,517,549 A1) and to adjust the vertical reel position (and in the case of EP 2,517,549 A1, also the reel speed and horizontal position) accordingly. While this automatic control allows adapting the reel parameters automatically to longer or shorter crop stalks, it will not work in a satisfactory manner in the case that (for example due to strong wind) downed crop is to be harvested, since in this case, the reel position for optimal crop collection depends also on the orientation of the downed crop, which cannot be detected by the mentioned sensors. In this case, manual control is thus still required.
It was proposed to sense the orientation of downed crop on a field based on texture or length of image segments with optical sensors provided on an unmanned aerial vehicle or on a harvesting machine in order to control the harvesting direction of the latter opposite to the lodging direction and to control harvester speed, header height and header orientation based upon lodging magnitude and direction (US 2017/0082442 A1). This proposal, however, offers no assistance to the operator in adjusting the reel control or cutter bar table position.
It is an object of this invention to provide an automatic platform header control system enabling collection of downed crop.